Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

ADM4850 Datasheet(PDF) 13 Page - Analog Devices

Part No. ADM4850
Description  5 V, Slew-Rate Limited, Half-Duplex and Full-Duplex RS-485/RS-422 Transceivers
Download  16 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  AD [Analog Devices]
Homepage  http://www.analog.com
Logo 

ADM4850 Datasheet(HTML) 13 Page - Analog Devices

 
Zoom Inzoom in Zoom Outzoom out
 13 / 16 page
background image
ADM4850/ADM4851/ADM4852/ADM4853/ADM4854/ADM4855/ADM4856/ADM4857
Rev. D | Page 13 of 16
CIRCUIT DESCRIPTION
The ADM4850/ADM4851/ADM4852/ADM4853/ADM4854/
ADM4855/ADM4856/ADM4857 are high speed RS-485/
RS-422 transceivers offering enhanced performance over
industry-standard devices. All devices in the family contain
one driver and one receiver, but offer a choice of performance
options. The devices feature true fail-safe operation, which
means that a logic high receiver output is guaranteed when
the receiver inputs are open-circuit or short-circuit, or when
they are connected to a terminated transmission line with all
drivers disabled (see the Fail-Safe Operation section).
SLEW-RATE CONTROL
The ADM4850 and ADM4854 feature a controlled slew-rate
driver that minimizes electromagnetic interference (EMI) and
reduces reflections caused by incorrectly terminated cables,
allowing error-free data transmission rates up to 115 kbps. The
ADM4851 and ADM4855 offer a higher limit on driver output
slew rate, allowing data transmission rates up to 500 kbps. The
driver slew rates of the ADM4852 and ADM4856 and the
ADM4853 and ADM4857 are not limited, offering data
transmission rates up to 2.5 Mbps and 10 Mbps, respectively.
RECEIVER INPUT FILTERING
The receivers of all the devices incorporate input hysteresis. In
addition, the receivers of the 115 kbps ADM4850 and ADM4854
and the 500 kbps ADM4851 and ADM4855 incorporate input
filtering. This enhances noise immunity with differential signals
that have very slow rise and fall times. However, it causes the
propagation delay to increase by 20%.
HALF-/FULL-DUPLEX OPERATION
Half-duplex operation implies that the transceiver can transmit
and receive, but it can do only one of these at any given time. How-
ever, with full-duplex operation, the transceiver can transmit and
receive simultaneously. The ADM4850/ADM4851/ADM4852/
ADM4853 are half-duplex devices in which the driver and the
receiver share differential bus terminals. The ADM4854/
ADM4855/ADM4856/ADM4857 are full-duplex devices that
have dedicated driver output and receiver input pins. Figure 28
and Figure 29 show typical half- and full-duplex topologies.
RO
RE
DE
DI
D
R
A
B
MAXIMUM NUMBER OF TRANSCEIVERS ON BUS: 256
RO
RE
DE
DI
D
R
A
B
R
D
RO RE DE DI
AB
R
D
RO RE DE
DI
AB
ADM4850/ADM4851/
ADM4852/ADM4853
ADM4850/ADM4851/
ADM4852/ADM4853
Figure 28. Typical Half-Duplex RS-485 Network Topology
GND
RO
DI
D
R
A
B
RO
DI
D
A
B
Z
Y
R
GND
VCC
VCC
Z
Y
ADM4854/ADM4855/
ADM4856/ADM4857
ADM4854/ADM4855/
ADM4856/ADM4857
Figure 29. Typical Full-Duplex Point-to-Point RS-485 Network Topology


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16 


Datasheet Download




Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn